Aplane layer of coal of thickness l = 1 m experiences uniform volumetric generation at a rate of q = 10w/m3 due to slow oxidation of the coal particles. averaged over a daily period, the top surface of the layer transfers heat by convection to ambient air for which h = 8 w/m2 ⋅ k and t[infinity] = 30°c, while receiving solar irradiation in the amount gs = 500 w/m2. irradiation from the atmosphere may be neglected. the solar absorptivity and emissivity of the surface are each α s = ε = 0.95.

Determine whether or not it is possible to compress air adiabatically from k to 140 kpa and 400 k. what is the entropy change during this process?

You are making beer. the first step is filling the glass carboy with the liquid wort. the internal diameter of the carboy is 15 in., and you wish to fill it up to a depth of 2 ft. if your wort is drawn from the kettle using a siphon process that flows at 3 gpm, how long will it take to fill?

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.